Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 114,124	$ 110,130
Accrued expenses	3,647	3,757
Tax credits	13,054	12,540
Bad debt	240	104
Inventory	4,056	4,821
Capitalized research and development	20,161	17,931
Equity compensation	2,965	2,669
Operating lease liabilities	3,239	0
Interest expense	8,418	3,718
Other	873	1,174
Deferred tax asset	170,777	156,844
Valuation allowance	(139,855)	(135,216)
Total deferred tax assets	30,922	21,628
Deferred tax liabilities:
Depreciation and amortization	(6,924)	(8,034)
Convertible debt	(12,878)	(4,149)
Operating lease right-of-use assets	(1,372)	0
Other	(230)	0
Total deferred tax liabilities	(31,072)	(21,778)
Net deferred tax liability	(150)	(150)
Trademarks and trade names
Deferred tax liabilities:
Intangible assets	(826)	(765)
Developed technology and trademark
Deferred tax liabilities:
Intangible assets	$ (8,842)	$ (8,830)